The suicide bomber behind an attack Tuesday that left 10 Germans dead in Istanbul’s main tourist area had registered with a refugee agency last week, providing fingerprints that allowed officials to quickly identify him, a Turkish official revealed Wednesday.

Turkish media, including newspapers close to the government, identified the bomber as Nabil Fadli and said he was born in Saudi Arabia. Turkish authorities previously had identified the bomber as a Syrian born in 1988 with links to the Islamic State terror group.

Turkish Interior Minister Interior Minister Efkan Ala on Wednesday confirmed reports that the bomber had registered with a refugee agency, but said the bomber wasn't on any Turkish or international watch lists for ISIS militants.

“Your assessment that his fingerprints were taken and there is a record of him is correct” he told reporters at a news conference, according to Reuters.

Turkey’s Haberturk newspaper published CCTV pictures purportedly showing Fadli at an immigration office in Istanbul on Jan. 5. It said he was traced to the bombing after authorities took a sample of a finger at the blast site.

The news about the bomber came as Turkish police arrested five people suspected of having a direct link to the attack.

One suspect was detained in Istanbul late Tuesday, Ala said. He didn't provide further details. Turkey's Prime Minister, Ahmet Davutoglu, later said four more suspects were arrested in connection with the attack.

Turkish police on Wednesday also arrested 13 suspected ISIS militants, including three Russians, but it wasn't clear if those arrests were directly linked to the Istanbul bombing.

The Russians were detained in the Mediterranean coastal city of Antalya, a popular destination for tourists. The state-run Anadolu Agency said the suspects were allegedly in contact with ISIS fighters in conflict zones and had provided logistical support to the group. Ten other people were detained in Turkey's third largest city, Izmir, and in the central city of Konya.

Turkish media said police raided a home in an affluent Istanbul neighborhood, briefly detaining one woman suspected of links to the Islamic State group, although it wasn't clear if she was the suspect Ala was referring to. The Hurriyet newspaper said the woman was detained because a mobile phone -- which she had reported stolen -- had been used to call the bomber. The paper said she was released after questioning.

The impact of Tuesday's attack, while not as deadly as two others last year, was particularly far-reaching because it struck at Turkey's $30 billion tourism industry, which has already suffered from a steep decline in Russian visitors since Turkey shot down a Russian warplane near the Syrian border in November.

The blast –just steps from the Blue Mosque in Istanbul's historic Sultanahmet district -- would be the first by ISIS to target Turkey's vital tourism sector, although the militants have struck with deadly effect elsewhere in the country.

The attack, which also wounded 15 other people -- including Germans, a Norwegian man and a Peruvian woman -- was the latest in a string of attacks by Islamic extremists targeting Westerners.

Germany sent a team of investigators to Istanbul on Wednesday from its Federal Criminal Police Office, which is comparable to the FBI, to support Turkish authorities investigating the attack.

Germany's Foreign Ministry said the number of dead Germans in Tuesday's explosion had risen to 10 but German Interior Minister Thomas de Maiziere said there was no sign that Germans were specifically targeted.

"According to the investigations so far, there are no indications that the attack was directed specifically against Germans, so there can't be any connection to our contribution to the fight against international terrorism," de Maiziere said.

Germany promised Tornado reconnaissance jets to aid military effort against the Islamic State group in Syria following the November attacks in Paris, and started flying missions from the Incirlik air base in Turkey last week. It also sent a tanker aircraft, as well as a frigate to help protect a French aircraft carrier in the eastern Mediterranean.

Germany already was helping supply and train Kurdish forces fighting ISIS in northern Iraq but has not taken a direct combat role.

Ala urged Turkish citizens and visitors to go about their daily lives, insisting that the country had taken "all necessary security precautions." He said Turkey had detained as many as 220 ISIS suspects in the week prior to the attack.

De Maiziere also said: "I see no reason to refrain from traveling to Turkey" or for people already there to break off their vacations.

Top German and Turkish officials already were scheduled to meet in Berlin next week to discuss Europe's migrant crisis, in which Turkey -- which borders both Syria and the European Union -- is a key player. De Maiziere said those talks will now also address "the determined fight against terrorism."

"If the terrorists aimed to destroy or endanger the cooperation between partners, then they achieved the opposite," de Maziere said. "Germany and Turkey are coming even closer together."

The German Foreign Minister Frank-Walter Steinmeier said his country would not make any further immediate changes to its travel advice for Turkey but could do so as the investigation into Tuesday's Istanbul bombing progresses. The Foreign Ministry advised Germans after the attack to avoid crowds in public places and outside tourist sites in Istanbul.

Regional authorities didn't identify the victims and gave ages only for some of them, ranging from 51 to 73.